The Tenth Schedule is a provision of the Indian Constitution, commonly known as the Anti-Defection Law. It was introduced in 1985 through the 52nd Amendment Act to curb the problem of political defection, which had caused significant governmental instability, famously termed the "Aaya Ram, Gaya Ram" phenomenon. The law was enacted to ensure stability in legislative bodies and uphold the mandate of the electorate.
The core mechanism is the disqualification of a Member of Parliament (MP) or Member of a State Legislature (MLA) on the grounds of defection, as outlined in Paragraph 2. A legislator is disqualified if they either voluntarily give up the membership of their political party or vote or abstain from voting contrary to any direction (whip) issued by their party without prior permission. An independently elected member is disqualified if they join any political party after the election. The authority to decide on a question of disqualification rests with the Presiding Officer of the House, the Speaker or the Chairman.
The Tenth Schedule is closely connected to the 91st Amendment Act, 2003, which significantly tightened the law. This amendment deleted the provision that exempted disqualification in case of a 'split' by one-third of the members of a legislature party. Now, disqualification is only avoided if a political party merges with another party, provided that at least two-thirds of the members of the legislature party agree to the merger.
A landmark judgment connected to the Schedule is Kihoto Hollohan v. Zachillhu (1992), where the Supreme Court upheld the constitutional validity of the Anti-Defection Law. The Court ruled that the decision of the Speaker/Chairman on disqualification is subject to judicial review on grounds like malafides or perversity, thereby limiting the finality clause in the original Schedule.